Lovén's Law described the position of larger basicoronal ambulacral plates in echinoids. The smaller basicoronal plates form first in ontogeny. We restate Lovén's Law to describe the position of first ambulacral plates using Carpenter's ambulacra and left (L) or right (R) as: AR, BL, CR, DL, ER, with EA the pair of ambulacra both identical and adjacent. First ambulacral plates of the Cambrian edrioasteroid, Walcottidiscus, code identically. The transition from a tri-radiate 1-1-1 pattern to the 2-1-2 ambulacral pattern of Walcottidiscus and other pentaradiate Paleozoic echinoderms results in Lovén's Law. This provides an hypothesis for the origin of Lovén's Law and predicts its widespread occurrence among echinoderm classes.The ‘BD different’ pattern of primary brachioles in pentaradiate glyptocystitoid Rhombifera results from subterminal branching of the ambulacra. The ontogenetic sequence was triradiate, then lateral ambulacra bifurcated, and finally second brachioles developed. Positions of second brachioles of pentaradiate glyptocystitoids code as AR, BL, CR, DL, ER. Other examples of Lovén's Law occur in Diploporita, Ophiuroidea, Edrioasteroidea, Edrioblastoidea, Holothuroidea, Ophiocistioidea, and Bothriocidaris. Our working hypothesis is that Lovén's Law arose with pentaradiality. An objective test requires a reliable independent landmark across all classes, which does not exist currently. Our hypothesis is only parsimonious if Lovén's Law arose just once in echinoderm evolution and is widespread within the phylum. So far, both conditions appear to be met, but edrioasteroid first ambulacral cover plates commonly exhibit an alternative Lovén-like pattern of AL, BL, CR, DL, ER, with AB the identical adjacent ambulacra.UUID: http://zoobank.org/4c40d338-8bfa-4515-9037-934f3bbab153

中文翻译：

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洛文定律在棘皮动物中的起源和意义

Lovén 定律描述了海胆动物中较大的基本冠状动脉板的位置。较小的基底节板首先在个体发育中形成。我们重述 Lovén 定律，以使用 Carpenter's ambulacral 和左 (L) 或右 (R) 来描述第一个 ambulacral 板的位置：AR、BL、CR、DL、ER，其中 EA 是一对相同和相邻的 ambulacral。寒武纪edrioasteroid的第一个ambulacral板块，沃尔科蒂迪斯卡斯, 代码相同。从三辐射 1-1-1 模式到 2-1-2 步行模式的过渡沃尔科蒂迪斯卡斯和其他五辐射古生代棘皮动物导致洛文定律。这为 Lovén 定律的起源提供了一个假设，并预测了它在棘皮动物类中的广泛存在。五放射状 glyptocystitoid Rhombifera 中初级腕骨的“BD 不同”模式是由 ambulacra 的亚末端分支引起的。个体发育序列是三放射状的，然后是外侧上肢分叉，最后发育出第二腕骨。戊二酸酯类糖囊腺素的第二腕骨位置编码为 AR、BL、CR、DL、ER。Lovén 定律的其他例子出现在 Diplorita、Ophiuroidea、Edrioasteroidea、Edrioblastoidea、Holothuroidea、Ophiocistioidea 和蚯蚓. 我们的工作假设是，洛文定律是由五辐射产生的。客观测试需要跨所有类别的可靠独立地标，目前尚不存在。如果洛文定律在棘皮动物进化中只出现过一次并且在该门中广泛存在，我们的假设只是简单的。到目前为止，这两个条件似乎都得到了满足，但 edrioasteroid 首个 ambulacral 盖板通常表现出 AL、BL、CR、DL、ER 的替代 Lovén 样模式，其中 AB 具有相同的相邻 ambulacral.UUID：http://zoobank.org/4c40d338-8bfa-4515-9037-934f3bbab153